Magnetic socket wrench



March 9, 1954 CLARK 2,671,369

MAGNETIC SOCKET WRENCH Filed Aug. 1 1950 Patented Mar. 9, 1954 UNITEDSTATES PATEN T OFI'CE WRENCH Frederick (3i. Clark, Bufialo, 3L, assignorof one-half to Wade Stevenson, Bufialo, N. Y. Application August 1,1950, Serial N 0. 177,)01 Claims. (01. 81-125) This invention relates toimprovements in magnetic socket wrenches of the type in which a magnetis employed for holding-a nut, bolt, screw or other article which is tobe rotated.

'One of the objects of this invention is to provide a socket wrench ofthis type with a magnet which is slidably mounted in the shank of thewrench in such a manner that very little pressure of the article beingheld and rotated is exerted against the magnet.

Another object is to provide a socket wrench of this type in which themagnet is yieldingly held in its outer position to engage the article tobe rotated, and in which the magnet may move into the socket against theaction of the yielding means as the article which is being rotatedadvances into the socket.

A further object is to provide a construction-of this type in which themagnet is arranged within a non-magnetic sleeve which surrounds asufiicient portion of the magnet to insulate it from the hollow shaft orshank in which it is arranged; also to provide a spring which isconstructed to bear against the non-magnetic sleeve of the magnet tourge the magnet into its outer position; also to secure within the boreof the socket wrench a bushing of non-magnetic material which forms astop to limit the extent to which the magnet will be moved by the springinto its outer position.

Other objects and advantages will be apparent from the followingdescription of one embodiment of. the invention and the novel featureswill be particularly pointed out hereinafter in connection with theappended claims.

In the accompanying drawings:

Fig. 1 is a longitudinal central sectional view of a socket wrenchembodying this invention.

Fig. 2 is an end elevation thereof.

Fig. '3 is transverse, sectional elevation thereof, on line 3-3,Fig. '1.

Fig. 4 is an elevation, partly in section, showing the magnet and thesleeve which is secured to the magnet.

In the particular embodiment of this invention illustrated by way ofexample, -5 represents a portion 'of a shank of a socket wrench which ispreferably, at least part, of tubular hollow cylindrical form. Only theouter end portion of the shank is shown in the drawing, and it will 2 beunderstood that the other end of the shank may tie-provided -withsuitable ine'an's for turning the same about its axis, either manually"or by means "of 'a power operated mechanism. The outer end of the shankmay, desired, be somewhat enlarged, as shown at '6 and shown, is

formed integrally -with the shank 5. This outer end of the shank isprovided With an interior surface which may be hexagonal oi-ef othernoncircnlar form and into which an article to be turned, such as a nut01 he'a'd cf a-sc'rew 1,:may exten'd so that the article will be rotatedwhen the shank 5 is rotated about its axis.

8 represents a pennanent'inag net "which, in the construction shown,is'cf the bar ty e having the opposite Fpoles thereof at the oppositeends of the magnet, or if desired, -the outer end of the magnet may beformed and magnetized -so that both poles are at this end of the magnet.This magnet may be "of any suitable cross sectional shape, for example,=circui'ai, as the construction illustrated, and is ='slidab'ly arran edwithin the hollow shank 5 with one end portion thereof extending intothe enlargement '6 thereof to hold the nut, screw 'or other article 7 bymagnetic force.

The magnet -8 :is partly "surrounded by a sleeve ID of non-magneticmaterial, such for example as bronze, brass or certain types ofstainless steel. The sleeve in is rigidly secured to the magnet 8 in anysuitable manner, such for example as by means "of a fit.A'consid'e'rable portion of the outer end *of the magnet extends beyondthe sleeve 1B and a les'ser portion of the inner end of the mag-netextends beyond this'sleeve.

Suitable means are provided for limiting the extent to which the magnetand sleeve can move outwardly toward the outer end of the shank, and

for this purpose, a bushing 12 is provided which is "of non-magneticmaterial and which is 'suitably secured to the shank 5 at the inner endof the bore thereof. When this bushing is secured in place, it will beobvious 'onan inspection of Fig. 1, that the bushing cocfperates withthe sleeve ill of the magnet to form a stop to limit the extent to whichthe sleeve to and magnet is held thereby may'move with reference totiiei hcllow shank 5.

The magnet is ry'relnnrgry urged into its outer position many suitahleand in'th'e construction shown by way of exampie, the inner end of thesleeve I is engaged by a coil spring H, the inner end of which may seaton the inner end of the bore of the hollow sleeve part of the shank, andthe outer end of the spring engages the inner end of the sleeve In aboutthe magnet 8. The spring is, consequently, confined in correctengagement with the inner end of the sleeve [0 by means of the adjacentend of the magnet which extends slightly beyond the inner end of thesleeve, and therefore, serves to center the spring H3 in reference tothe sleeve [0.

The sleeve is provided at the outer end thereof with an outwardlyextending, conical face l6, and the bushing I2 is preferably providedwith a correspondingly shaped, inner conical surface l'l. These twoconical surfaces serve to center the sleeve l0 and the magnet 8 withreference to the hollow shank 5, so that the outer end of the magnetwill be arranged substantially cen trally in the inner, non-circularbore of the enlarged end 6 of the shank.

Since the sleeve l0 and bushing [2 are both made of non-magneticmaterial, the shank 5 and the extension 6 thereof may be made ofmagnetic material. Consequently, when the nut, bolt or screw 1 isarranged within the enlargement 6 of the shank, this nut or head will besubjected to the maximum magnetic force and if the magnet has its polesat its opposite ends, the magnetic circuit will extend from the outerend of the magnet through the nut or head 1 to the part 6 and the shankto the other end of the magnet. The spring [4 is preferably made ofmagnetic material, so that some of the magnetic flux will pass from theshank through the spring adjacent the magnet 8. By providing a magneticcircuit which is substantially free from air gaps, the article is heldby the maximum force which the magnet can exert.

In the use of the socket wrench described, the article I is insertedinto the non-circular bore of the sleeve and is held within this bore bythe magnet 8. However, when pressure is applied by the article againstthe magnet, it will move inwardly into the hollow shank 5 against theaction of the spring I 4 to any desired extent, so that no materialpressure will be exerted against the magnet. Since magnets of the highpowered type, such as those of Alnico alloy, are quite brittle, thisspring backing of the magnet will prevent damage to the magnet whenforce is applied to the same by means of the nut or other article.Furthermore, the construction of the wrench is such that if a nut isheld in the socket to be applied to a threaded bolt or stud, after theend of the bolt or stud projects beyond the nut, this end may enter intoand through the bushing l2, with the result that the magnet 8 will bepushed farther into the hollow shank against the action of the spring l4without damage to the magnet. When the socket wrench is withdrawn fromthe nut or other article, the spring will again force the magnet intoits outer position, shown in Fig. 1, for cooperation with anotherarticle, and the inclined faces l5 and I! of the sleeve and bushing willtend to center the magnet within the shank 5 and extension 6 thereof.Furthermore, during the movement of the magnet back and forth in thehollow shank 5, the magnet will be held out of contact with the hollowshank, and any wear resulting from the movement of the magnet back andforth into and out of the hollow shank will be taken by the sleeve I 0.The sleeve, furthermore, serves to center the magnet in the wrench.

The term "non-magnetic is herein used in the practical sense todesignate materials of very low magnetic permeability.

It will be understood that various changes in the details andarrangements of parts, which have been herein described and illustratedin order to explain the nature of the invention, may be made by thoseskilled in the art within the principle and scope of the invention asexpressed in the appended claims.

I claim as my invention:

1. A socket wrench including a hollow shank made of a material permeableto magnetism and provided at the outer end thereof with an internalnon-circular bore for receiving the articles to be rotated by thewrench, a magnet slidable in said shank, a sleeve of non-magneticmaterial covering only a portion of said magnet and cooperating withsaid hollow shank to guide the magnet in its movement lengthwise withinsaid shank, a bushing of non-magnetic material through which anon-covered portion of said magnet may pass and which is secured to saidshank and cooperates with said sleeve to limit the extent to which saidmagnet may move outwardly in said shank, and spring means arranged insaid hollow shank and urging said magnet into its outer position andpermitting said magnet to be moved into said shank.

2. A socket wrench including a hollow shank made of a material permeableto magnetism and provided at the outer end thereof with an internalnon-circular bore for receiving the articles to be rotated by thewrench, a magnet slidable in said shank, a sleeve of non-magneticmaterial extending about a portion of said magnet and cooperating withsaid hollow shank to guide the magnet in its movement lengthwise withinsaid shank, said magnet extending at its inner end beyond said sleeve, acoil spring in said hollow shank made of material permeable to magnetismand having the outer end thereof engaging said sleeve and extendingabout the end of the magnet which projects beyond said sleeve, the otheri end of the spring being seated in said sleeve and forming a part of amagnetic circuit which includes the articles being held by the magnet.

3. A socket wrench including a hollow shank made of a material permeableto magnetism and provided at the outer end thereof with an internalnon-circular bore for receiving the articles to be rotated by thewrench, a magnet slidable in said shank, a sleeve of non-magneticmaterial extending about a portion of said magnet and cooperating withsaid hollow shank to guide the magnet in its movement lengthwise withinsaid shank, said magnet extending at its inner end beyond said sleeve, acoil spring in said hollow shank made of material permeable to magnetismand having the outer end thereof engaging said sleeve and extendingabout the end of the magnet which projects beyond said sleeve, theinwardly extending end of the magnet and said sleeve forming an annularseat in which the outer end of said coil spring is seated.

4. A socket wrench including a hollow shank provided at the outer endthereof with an internal non-circular bore for receiving the articles tobe rotated by the wrench, a magnet slidable in said shank and having theouter end thereof extending into said non-circular bore when said magnetis in its outer position, resilient means urging said magnet into itsouter position and permitting said magnet to move into said hollowshank, a sleeve of non-magnetic material secured to and covering onlythat portion of said magnet remote from said outer end thereof, and stopmeans in the form of a bushing of nonmagnetic material secured withinsaid hollow shank, said sleeve cooperating with said bushing to limit.the extent to which said magnet may move outwardly in said shank.

5. A socket wrench according to claim 4, in which said bushing and saidsleeve are provided with cooperating tapering faces converging towardthe axis of the wrench which serve to center the magnet in said hollowshank when said magnet is in its outer position.

FREDERICK G. CLARK.

6 References Cited in the file of this patent UNITED STATES PATENTS NameDate Keyes Jan. 9, 1894 Trumbo May 6, 1904 James Feb. 10, 1925 WoockJan. 12, 1937 Reardon Oct. 21, 1941 Brown Mar. 3, 1953

